ope.math: operator product expansions in free field realizations of conformal field theory

Coupling of Two Conformal Field Theories and Nakajima–Yoshioka Blow-Up Equations

“…The main tool of the proof is a Drinfeld-Sokolov reduction of the representation of sl(2) 1 ⊕ sl(2) k with respect to the diagonal sl(2) k+1 . Some arguments were based on the explicit computations which were made using Akira Fujitsu ope.math package [17].…”

TOPOLOGICAL STRUCTURE IN $\hat c =1$ FERMIONIC STRING THEORY

“…We would like to thank M. Kato for many useful discussions and comments on the manuscript. We are indebted to A. Fujitsu for his package ope.math [21]. This work is partly supported by the Japan Society for the Promotion of Science.…”

Lambda: A Mathematica package for operator product expansions in vertex algebras

“…One way to define a normal order product of operators in quantum field theory is by point splitting. The singular terms captured by the OPE between the operators, are subtracted from the product: 9) and the result is a well-defined operator at z. In vertex algebras, the normal ordering product is defined in a similar way; by acting with the non-singular part of a field A(z), in the limit z → 0:…”

“…The most used seems to be OPEdefs [8]. Also see [9]. The package OPEdefs has been developed further to handle N = 2 superfield in [10].…”